It's the second helicopter-aided inmate escape in Quebec province in two years.
Provincial police said the helicopter headed west from the Orsainville Detention Center after the escape.
"We (are working with) a few partners like the airports of Quebec City and surrounding areas, the military bases, and of course there's a ground search in the event that the helicopter is located," said police spokeswoman Audrey-Anne Bilodeau.
Police identified the inmates on Twitter as Yves Denis, Denis Lefebvre and Serge Pomerleau and told anyone who sees them to not approach them and immediately contact police.
In March of last year, a helicopter pilot was forced at gunpoint to pluck two inmates from the St-Jerome prison on a quiet Sunday afternoon. Two inmates climbed up a rope ladder into the hovering helicopter and fled.
Police caught the two escapees and the two suspects who hijacked the helicopter within a few hours of the escape.